I need help with this money math problem.?

Question

this is rather simple, but i just woke up and i can't figure it out, lol. my brain isn't processing.

anyway, i have $12.90 and they charge 8.9 cents per dollar. so how much money would i have after i pay the fee?

(i'm going to the supermarket for CoinStar) =D

please don't say, "just go to the bank, they exchange for free" because even if that IS true, i don't have a ride. the supermarket is just a few blocks away. all banks are like, clear across town. thanks! =D

Answer 1

12.90*.911=11.75

where's your coffee?  ;-)

'course, if you use google calculator, you can say:

12.90*(1.00-.089)=11.7519

Answer 2

$12.90 x .089 = $1.148 rounded off to $1.15

$12.90 - 1.15 = $11.75 Coinstar will reinburse you.